The Gray Whale, Part 3

Published Mar 9, 2023, 4:30 PM

In this episode of Stuff to Blow Your Mind, Robert and Joe discuss the enigmatic gray whale, noted today for its vast oceanic migrations and curiosity, but known as “devilfish” for its ferocity by the American whalers who hunted it in the past. (part 3 of 3)

Welcome to Stuff to Blow Your Mind production of iHeartRadio. Hey you welcome to Stuff to Blow Your Mind. My name is Robert Lamb and I'm Joe McCormick, and we're back with Part three, the final part in our series on gray whales. Now in the previous episodes, which if you haven't listened to yet, you'd probably go back and check out parts one and two. First, in the previous ones, we described the morphology and behavior of the species scientific name is Shrichtius robust us. There the robust buddies, the gray whales, and we talked about their relationship with the barnacles that often pile up on them like a like a big old nasty crust. And we talked about their relationship with their main predator other than humans, the orca. And today we're going to kick off addressing their amazing migratory habits, which is probably one of the main things to understand about this species. Yeah, yeah, And to sort of draw back to those previous episodes that reiterate that I did get the chance to see gray whales in the wild at their breeding lagoons, A particular one of their breeding lagoons called Ojo Delia Gray Lagoon on the Baja Peninsula about halfway down the Baja Peninsula, and it was an amazing experience. So I'll refer back to to some of my observations alongside the various sided materials that we're going to be referring to now speaking of those breeding lagoons. In the last episode, you know, we mostly discussed these as the safe waters for the birth of the whale calves and a reason for migration in gray whales in particular. But as highlighted in one of the books that I was using here, whales their biology and behavior by Hammond at all, there are other considerations to take into account concerning, first of all, just migration of bailing whales in general. So on the reproductive front, yes, protection from orcas does seem to be a major factor, particularly with gray whales, and there's the additional hypothesis that the whale calves to survive and grow better in warmer waters. It's also argued that it's simply energetically more efficient to swim to warmer waters than to overwinter up north. There's also more visibility and shelter in tropical waters. We talked, and this comes back to orcas survival to a large extent, we discussed the gray whales ability to seek shallower waters, and part of that is that there it sounds like they're just more nooks and crannies that the whales may venture into to find refuge. Yeah. So, for example, when gray whales are threatened by orcas, it's been observed that they might try to seek shelters, say in kelp beds, or like in hiding in seaweed, or even in breaking surf, which apparently helps obscure their presence. Yeah, and we'll come back to some more details about this in a minute. The authors here do stress, however, that there's just there's no one size fits all explanation, especially considering that there are various differences in behavior among the baling whales in general. For instance, they mentioned that one factor for many baling whales, again not gray whales specifically, but but other filter feeding whales, seems to be that during the summer you have a stratification of the water column to include a highly photic zone, resulting in rapid photosynthesis and reproduction of phytoplankton. Phytoplankton are the plant plankton, and these phytoplankton in turn feed the zooplankton, which of course are the animal plankton, and this generally fattens up the entire ecosystem in these waters. But then in the winter, cooling temps and strong winds break up the stratification, mixing the vertical water column. Phytoplankton can't stay near the surfaces easily, there's increasingly less sunlight and prey availability takes a dive as well. Okay, so the plankton scene kind of dries up a little bit. Yeah. Now, as we mentioned, and I believe the first episode, gray whales are of course rather different than a lot of the other baling whales, I mean, all the other extent baling whales, because they're not really going after things like kelp and zooplankton. No, they're going after those benthic organisms like isopods in the sand on the sea floor. So they're not directly feeding for the most part on plankton. However, the benthic organisms down there are still part of the food web and are therefore impacted as well by all of this. Okay, so if you don't recall we described their typical feeding behavior, I think in part one of this series where unlike the whales you've probably seen kind of like zooming around near the surface of the water and just like letting water wash into their mouths, filtering out all of the plankton or the krill or whatever with their billing. The gray whales have a habit of slamming their heads into the sediment on the ocean bottom in relatively shallow areas to sort of like scoop up a bunch of this sediment and then getting like use their billiing to filter the organisms out of it and eat those. Yeah, exactly like basically scraping one side of their face across the seafloor. Now there's another interesting factor in all this. So we mentioned in one of the previous episodes that gray whales have been observed in recent years overwintering in the Arctic and not making the migration down south in rare instances. And I don't believe we're talking about reproductive or currently reproducing females in these cases. But basically this is a situation where we have to consider climate change. Once again. We have to remember that climate change has some of its more drastic effects in the Arctic. And I was reading an interest in OAA paper dealing with some of this, titled Sentinels of Change Gray Whales in the Arctic, pointing out that less sea ice means more exposed ocean areas and this alone has a huge impact on the environment. But they also point out the following. So in cold years, what you have happening first is a spring bloom of plankton. But in the early spring, most zooplankton are not yet ready to graze. Meanwhile, the phytoplankton, the plants digging all that sunlight, they're just going crazy, and there's so much of it that the zooplankton are in. The zooplankton are not ready to feed on it yet, so most of it ends up sinking to the bottom. And what happens at the bottom, well, that's where the benthic organisms are and they feast on them. And again that is what the gray whales are primarily going to eat, those creatures down there that just date all of this phytoplankton. In warmer years, however, the sea ice melts too early. There's not enough light to really power up the spring bloom of phytoplank and so the phytoplankton bloom is delayed and it doesn't really hit until of the zooplankton is fully ready to feed, meaning that the zooplankton can eat most of it, there's less to rain down to the menthic organisms. Okay, so that sounds not great for gray whales. That's what it would sound, right, yeah, because that's their primary feast down there. But what this particular paper stresses is that as warmer years likely continue due to climate change, we might see gray whales shift in their diet. So we mentioned that they're fairly opportunistic, so they will do some filter feeding in the upper portions of the water So if they aren't able to get what they would normally get down there at the bottom, or it seems like there's more, say zooplankton in the upper portion of the water column, then they will eat that and potentially eat that instead. So it's a situation where they outline that a couple of things happened. We might to see them displaced from their traditional feeding grounds, but we also might see a portion of their diet shift more in favor of filter feeding upwards in the water column, eating more zooplankton than would normally make up their diet and I think, goodness. I'm trying to remember what the percentage was when we talked about it, but it's like a huge percentage of their known normal diet is those benthic organisms down there in the sand. So it's kind of a good news not I don't know if it's a good news bading situation, but anyway, it speaks to these organisms have been around for a long time, and part of their ability to survive has been their ability to make reasonable adaptations. Yes, and I guess that brings us back to the issue of the migration, because what we're talking about right now is primarily what's happening in their feeding grounds in the Arctic waters. But that's only half of the story. That's really fatten up up north, especially when we're talking about this population of the Eastern Pacific gray whales. The other half of the story is reproduction, which involves a journey south. That's right, and this is quite a journey for the gray whales. The distance between their summer feeding grounds and their winter breeding grounds can exceed twenty thousand kilometers. That's something like twelve four hundred and twenty seven miles. Now, it's worth discussing again again These are not deep ocean whales, and that makes sense given their diet. They primarily stick to a shallow continental shelf waters. They stick reasonably close to the coast, and therefore we see that reflected also in the way they migrate between these two waters. They're not making a bee line from one area to the next. Their journey tends to be more coastal, with some alterations depending on exactly what their circumstances are. Now, we mentioned that there used to be a population of North Atlantic gray whales, and it's thought that they would have fed around Newfoundland, the Gulf of Saint Lawrence, Iceland, and Europe's North Sea. And it's thought that they would have found winter breeding refuges somewhere along the coasts of Georgia and the Carolinas here in the States, as well as uncertain spots along the coast of Spain, Portugal, and Morocco. Now, this population was essentially extinct by the late seventeenth and early eighteenth centuries do at the very least in large part to whaling, if not largely to whaling or entirely to whaling. Interestingly enough, there have been proposals to try and reintroduce North Pacific gray whales into this region to restore the population. I think we mentioned this previously. And there's also the possibility that they may recolonize the area themselves as in the future as sea ice melts and opens up these waters to them once again. So the North Pacific population potentially recolonizing the North Atlantic, but that's kind of hypothetical. We're not sure exactly how that would pan out, though, I guess it's always possible, because occasionally you do find whales like way outside of their their normal ranges, right, They just kind of pop up in strange places that that you don't usually find them. Yeah, there are a couple of outstanding examples of that. Did Carboning points out a single gray whale was sighted off the coast of Israel in twenty ten, and in twenty thirteen one was seen off the coast of Namibia, and it's uncertain exactly why in both of these cases. Hammond at all point out that their origin was was almost certainly the North Pacific population in both cases though, Yeah, that's great. How would they get that far away? Yeah, I mean, I guess we know they can swim away as due to their to their habitual migrations. But yeah, you want to know the story of that wandering whale. Yeah. Now, now coming back to that now extinct North Atlantic population. Quick Outlander note out for everyone out there. I was reminded of this, My wife reminded maybe that we had watched this. But the television series adaptation of Outlander has a scene set on the coast of South Carolina, and again this is about time travelers going back in time, in which two of our time traveling characters remark about some whale activity off the coast and how they wouldn't have seen this in their original timelines or in the original times and the footage they use in the show, I had to check it. It's not gray whales that they're they're using here, I believe, but it certainly made me think of the scenario that you're like, Yeah, if you went back in time before human whaling activity seemingly had a chance to just drastically alter the ecosystem in the Atlantic, you would have potentially seen these great whales, Like it would have been possible for me to see gray whales in my home state of Georgia, potentially without having to travel to the other side of the continent and then to another country. And when is this set an outlander? Is this like early eighteenth century or something. Yeah, the initial transplant I think is from nineteen forty five to seventeen forty three. Okay, Yeah, and certainly, as we'll discuss, given the population changes in the gray whale at nineteen forty five, it was a bad time for the gray whale anyway. This also reminded me of something that our previous guest on the show. This, I think was while you were out Joe, I talked with Ryan Tucker Jones, author of the book Read Leviathan, which is largely about Soviet whaling in the Industrial Age, but it also discusses just the history of whaling in general, and it's it's a fascinating look at like why the Soviet Union got increasingly into whaling during the Industrial Age and the impact of it, what was also learned scientifically from it. And there's a there's a bit in that. This is just from the introduction where he writes, quote, as someone who grew up in Oregon and California in the nineteen eighties, I experienced the ocean at the whale's lowest point, an ocean that had been created by the Soviet Union as much as anyone. The history of Soviet whaling belongs to anyone who looks out to the sea and sees nothing. Oh yeah, it's there. Are a lot of really haunting moments in the book and just a lot of great details. Certainly go back and listen to that interview for more or or just check out the book. Just a reminder that the gray whale in particular was hunted near the point of extinction by humans. We slaughtered them on their migration routes. We slaughtered them in their northern feeding grounds, and we slaughtered them in their breeding lagoons. They were afforded full protection in nineteen forty six. Those Soviet whalers took three hundred and twenty hundred scientific permit in nineteen sixty, along with another one hundred and thirty eight illegally. These figures according to Carwadene in Carveding Just in case you don't remember, I haven't cited him in this episode, but that's Mark Carwadine's Handbook of Whales, Dolphins and Porpoises of the World. But adding more context from Jones here, he notes that by the end of the classical age of whaling, so the pre industrial sailing age of whaling, the sort of moby Dick era of whaling. Quote, humans mainly Americans, had reduced Pacific gray whales from around twenty four thousand to a remnant population of two thousand. Atlantic gray whales were entirely extinct, and so from what I understand today, Atlantic gray whales they are gone for all we know. And then there are the two populations. There is the Western Pacific gray whale, which lives along the eastern coast of the Asian mainland. That population is, from what we can tell, in pretty rough shape today. I don't remember how many individuals it's down to, but it's estimated to be pretty low, whereas the Eastern Pacific gray whale along the coast of North America is doing okay. Yeah. And in terms of the classical and industrial whaling, like, certain species were impacted more in different in different phases. So the gray whales were slower and they tended to be closer to shore, so in many respects they were easier to catch during that classic age of whaling. Though like we mentioned, they they were the devilfish. They could certainly put up a hell of a fight as well. But as the age of industrial whaling brought many of the faster species like blue whales and fins into the sort of whaling fold, here those whales had fewer defenses against whalers. They'd really only ever had to contend with orca jones rides. But meanwhile, in the age of industrialized Soviet whaling, quote, gray whales were particularly tricky. Soviet whalers noted that, despite being slow, the gray was the only whale and he quotes about which no rules of catching have been established. Only on rare occasions did gray's move in a straight line, instead usually swimming in zigzags, making movements to one or the other side without determined direction. Science the Soviets hoped might help establish some or other pattern to its movement. I wonder if the ways that different whales reacted to threats by human whalers was affected by the different strategies these species had for dealing with orca. Obviously, the threats posed by human whalers and orca are going to be of a very different shape and nature, but maybe some anti predator strategies aimed at orca were just also just also happened to buy coincidence be better at evading human whalers. Yeah, it sounds likely because certainly the end, one of the things about the industrial ages, you just had faster ships and they could keep up with with whales and they could get those whales that were further out. So gray whales in the North Pacific were greatly reduced by this time, and those that remained even were even harder to acquire. Jones also notes that by nineteen thirty six, the average size of gray whales captured was greatly decreased, and the reasoning hero was quote the population was no longer seeing its members to adulthood, because again, these are creatures that can live I think upwards of late like eighty years or so if I'm remembering correctly, and they're just they that's how impacted the population was now today. Caring notes that while gray whales in general have greatly rebounded, and like, if you look them up online, you'll quickly see that they're listed as least concern as far as conservation status goes, which is which is great news. That's a heck of a comeback story. But they're still threatened by oil and gas developments in the Arctic and and declining sea ice. Other threats include entanglement in fishing gear, occasional illegal harpooning, chemical pollution, noise pollution, ship collision, and the expansion of sea salt production in Baja California. In my own experience down there in Baja California, I mean, the lagoon that we ventured out too in order to see the whales was surrounded pretty much only by salt industry projects, so I can understand where that would be a concern. Carveding also notes that while the Eastern North Pacific group is doing great at the moment, there was you to see some fluctuations. So there was a six hundred and fifty one whale die off in nineteen ninety nine through twenty eleven, and that would have been like a twenty three percent population die off, though this doesn't necessary daily reflect long term survivability according to the NAA, and you can have big swings in population like that and it doesn't necessarily speak to how the species is doing long term. But that Western North Pacific population, like we said earlier, this one, according to Carvedin, is quote, one of the most endangered whale populations in the world. So even though the species at whole is doing better, we're mostly looking at the Eastern North Pacific group as opposed to the Western North Pacific group. Again, to whatever extent, that's a true separate population because we do see overlap in their breeding and behavior. So getting more back into just the migration patterns here that are pretty fascinating. We have the North Pacific gray whale to contend with here, and you have these two basic groups. The Eastern North Pacific grays migrate between those Baja California breeding lagoons and summer feeding grounds and the bearing chuck Chee and Beaufort seats, though this range is expanding as the ice opens up again. The Western North Pacific grays migrate between winter breeding grounds somewhere in the South China Sea to summer feeding grounds in the Sea of Okoksk and parts of Kamchatka, and there is some mixing of these groups in both the summer and winter. Now, the Eastern North Pacific grays have the longer of the two migrations, spanning up to fifty degrees of latitude according to Carwadine, and the shortest return journey for these whales is about twelve thousand kilometers or about seven thousand, four hundred and fifty six miles. He adds that the longest documented migration of any mammal was a female gray whale with a twenty two thousand, five hundred and eleven kilometer round trip between sakal And Island, Russia and Baja California, Mexico. So that would have been again that we're talking about how there is overlap in the ranges of the eastern and western. Now note that there's also apparently a two hundred strong Pacific coast feeding group that doesn't migrate all the way up to the Arctic at all, but feeds off a coastal area stretching between northern California and southeast Alaska. And there's another group that feeds im Puget Sound. So all right, here are the stages of the migration, and in covering these stages, we're going to hit on some of the things we've discussed already, but try and keep it reasonably. It's the sink here. But first we'll start with leaving the Arctic. Okay, they've been feeding. The whales have been feeding up north, and the signal of the head south seems to be a combination of the formation of sea ice and the decreasing day length. Apparently ninety percent leave the bearing sea through intimac Pass on a sixty day journey to Baja California, a near term mother's leave first, then other adults, then immature females, and then immature males. The last are on their way south while the first group is already on their way back north. Again. Oh, that's interesting. The orca threat is far less during this part of the cycle. Again referring back to the the orcas. The orcas are are are intelligent and cunning in their hunting of these dangerous, uh, these fearsome prey species. So at this point, the whales have been feeding all summer long, so they're they're they're fueled up, they're they're ready to fight, and their their calves are are even larger than they were previously. So everybody's stronger, everyone's well fed. It's not to say the orcas won't feed or won't attempt to acquire prey, but this is not the optimal time to do it. And a reminder of what we talked about last time, uh, this would be related to the fact that orcas are going to be mostly trying to prey on newborn whale calves for their return journey coming up the migratory corridor back to the feeding grounds, because a healthy adult gray whale is a pretty hard target, and orcas are observed to not never, but very rarely try to attack a healthy adult. Usually what they're trying to do is separate a young calf and and prey on it. Yeah, exactly. So they make their way south, and then it's lagoon time, and there are three main areas that they gather here. The exact amount of time spent in the lagoon's berries depending on sex and the presence of calves. Females with young cows just going to hang out far longer because you know, they need to bring get that that young one up to wait up to strength before they head back out again. Whereas like a male that's come down to breed, you know, obviously he doesn't have to stay as long's he can head back up as soon as he's ready. As we've discussed, these waters provide shelter against the orca, but they don't provide food. The adult whales don't feed while they're in the lagoon, and the whales that are born here while they drink their mother's milk, and of course that is you know, just going to sort of drain the mother is even more so this makes it really important that they fatten up as much as possible before the journey south exactly. Yeah, like we said, they seem safe from the orca here because the orca are hesitant to enter into shallow waters where they won't be able to employ their full range of pack hunting techniques. And also where I don't know if we mentioned this either, but there are a lot of whales in these waters. Like when I was out there, you'd see just they were everywhere. There were just hundreds of them. In fact, I saw they had a tallied count even at the whale center there and the figures I'm pulling this up on my phone. I took a picture of it, but the total count for mothers with babies was three hundred and twenty two. The lonely whale count was two eighty seven. So like this is just the count, but it was like nine hundred and thirty one whales already during that that breeding season. So another reason I guess to tread carefully. If you're an orca, you know you're going to go into this area where you can't use all of your tactics, and there are tons of whales that, as we mentioned, may work together against you if you present yourself as a threat. Right, But that doesn't mean they don't know about these lagoons, that mean they don't occasionally even venture in on a scouting mission. They're out there beyond the limits of the lagoons more or less waiting because again, as Carveding points out, the orca choose to strike quote when natural features tip the balance in their favor. All right, So, but eventually it's time to head north again. These they haven't been feeding. Everyone needs to get back to those feeding grounds. So first all the whales except mothers and calves leave, and they tend to take the more direct route that has brought them there. So, for instance, if there's a you know, they stick more or less to the coast, But if there's an area where there's like a bay or something, or a little inlet, they're more likely to just go straight across that inlet instead of hugging the coast through all the milks and crannies. Right, a little more as the crow flies, right, But when the mothers and calves leave. This is about one to two months later. The calves have grown stronger on and it's there they're far more prepared than they were to head out into these dangerous waters. But it ends up also being a longer trip for them because they are going to stick closer to the shore. They are going to travel around all the contours of the shore, you know, as much as as possible, rather than crossing or cutting corners. And I think it's pretty obvious why right, Because, as we discussed last time, one of the main anti predator strategies of the gray whale trying to get away from an orca attack or orca harassment is to retreat into the shallows, where the orcas certainly can't attack effectively and often won't even try to follow right. So for this reason, they tend to stick within two hundred meters or about six hundred and fifty six feet of the shore, often moving through kelp beds. Now, this is definitely the most dangerous part of the whole migration cycle, though in general the return trip, because the calves have had a month or two to grow and gain strength, but they are still at their most vulnerable during this leg, so you know, the mothers that are protecting them have not fed in months, and then increasingly as they move north, I mean they're they're also going to grow a little bit weaker. They've only had the milk to feed off of. And then again the orca are going to strike wind conditions are most optimal for them. And generally there are two major known attack spots along the journey attack hot spots, as the literature refers to them. One of them is Monterey Bay in California, and the other is Alaska's Unamaic Pass. Unamat Pass is the most popular of the two, and this has to do with the fact that both the mothers and the calves are kind of at optimal weakness here. This is further north on the return trip, so like everything is tipping in favor of the the orca at this point, and so a number are just going to be picked off during this period. That's just how it goes, that's the cycle of predation. But enough are going to reach those northern waters, and at that point this whole cycle begins again. They reach the northern waters, it's time to feed, to gain strength, to fatten up, and the whole cycle continues and of course, part of this whole cycle is the barnacles, because the barnacle. Again, those calves are born without the barnacles, but those barnacles will grow. The life cycle of the barnacles is tied up with the life cycle and the travels of these whales. That's right. We are never without our barnacles, are we, whether metaphorical or literal. So gray whales, just to do a quick refresher on our previous discussions about whales and whale barnacles, gray whales and other species such as humpbacks and so forth, are regularly found carrying a large load of barnacles. And a barnacle is a filter feeding crustacean. It's kind of like a tiny shrimp that is stationary for the adult portion of its life. So a barnacle will generally swim around as a larva as a young ling, and it will find a suitable substrate, then cement its head to that substrate, and then build a hard shell out of calcium carbon plates. And these shells can take many different forms. They can look like anything from a concrete pumpkin to a little volcano, and then they live by filter feeding. They wave these little legs called cerri out in the water to catch bits of plankton and pull them in and eat them. Some species of barnacle specialize in living on the bodies of whales, and this is of course great for the barnacle because it provides a steady flow of water to feed from. Barnacles. Often, when they're not on whales, many barnacle species try to find a spot in the intertidal zone where the tides are going to be moving waters over them in and out all day, because they need moving water to help catch their food, to bring food to them. I think the way we put it was that they need high foot traffic areas. So latching onto a whale is a great adaptation. That's gonna have water flowing over you all the time as the whale swims. But also it's very helpful in that it provides protection from predators. And you can see some evidence of this in the size that whale barnacles grow to and in the fact that they often have a shell or plate design that is less defensive looking, like they close less completely and often have more fleshy bits just kind of poken out all the time. So this relationship definitely helps the barnacles. But how does it affect the whales. That's not entirely clear. We talked about some arguments several different ways in the previous episode. It may hurt the whales by causing drag during swimming, would of course reduce swimming speed and efficiency for the whale. It might possibly also help the whale in some cases by providing kind of armor plating for violent encounters with orcas or interest specific aggression between say male humpbacks during mating season, but that's not certain. That's a maybe. But whatever the effect on the whales, it is normal to find gray whales covered in hundreds of pounds of barnacles by adulthood, so they've got a bunch of barnacles on there. In fact, gray whales have a particular specialist type of barnacle that is unique to them called crypto lapos rakianecte. So that's the background. But I wanted to come back to barnacles because I was reading a really interesting article in Hakai magazine by an author named Mara Gruenbaum. This was published in November twenty twenty one, and the article is called what whale barnacles? No very interesting article worth looking up and reading in full, but I just wanted to mention a few elements from it that caught my attention. So one thing I don't think I fully clocked when we talked about whale barnacles in the previous episode is how big some of them get. Was some species of whale barnacles grow very large compared to most barnacles you would find attached to stationary surfaces. The article here compares them at the upper end to several things. Compares them to the size of a coffee mug, a tennis ball, or a clementine orange. Rob. I don't know how big the barnacles on the gray whales you saw were, but some of these photos I've now seen with other objects for scale makes you realize, like, wow, those are some some beasts. Yeah, I mean the ones I saw were pretty large, and then of course you would you would sometimes see them clump together as well, so that kind of adds to the feeling. But individually, yeah, some of them are quite large. So there's one fact that is off handily alluded to in this article that I hadn't come across before, and it made me want to do some digging because I found it fascinating. But there is a passage where Grundbaum rites quote these unbudging appendages speaking of whale barnacles, of course, which colonize a dozen odd different whale species, latch on so tightly that they are practically part of the whale's skin. As a result, they were carried into caves by Southern African people who foraged washed up whale meat one hundred and sixty four thousand years ago. So WHOA, that's an image prehistoric people foraging whale meat. I don't know why I wouldn't have imagined that happened before, but it totally makes sense, so I decided to look up the primary evidence for this. I believe the author here is citing some findings from a place called the Pinnacle Point Cave thirteen b in South Africa, in which fragments of whale barnacle were found, But this is not, in fact the only case of whale barnacles being found away from the ocean in caves inhabited by prehistoric peoples, giving evidence that these people foraged whale meat. Another example I came across was a cave in Spain. This was written about in a paper by Esteban Alvarez Fernandez at All published in the Quaternary Journal in twenty fourteen. Paper is called occurrence of Whale barnacles in Nurja Cave, Malaga, Southern Spain Indirect evidence of whale consumption by humans in the Upper Magdalenian and the authors write, quote, whale barnacles indicate that maritime oriented forage or human groups found stranded whales on the coast and because of the size and weight of the large bones, transported only certain pieces such as skin, blubber, and meat to the caves where they were consumed. And so we have this evidence of consumption of whale flesh soft parts of whale flesh, not the bones in these human caves, because the barnacles are in there. How else would the barnacles get into these human inhabited caves. They're stuck to whales all the time. So because many whale barnacles are adapted to a particular host species, you can also tell in these cases what type of whale meat the people were eating, and in this case it was two different species of barnacle that are found on the southern right whale. That's also interesting because these whales are only found much farther south today, but the author's right quote. Because of Antarctic sea ice expansion during the last glacial period, these whales could have migrated to the northern hemisphere and reached southern Spain. Oh wow, that's fascinating. So these are not gray whales. But because gray whales also have associated barnacle species, you could, by the same method, potentially identify ancient ranges of gray whales by looking for evidence of their dedicated barnacles. And there's another way this article gets into that. You could look at the prehistory of whales that look at the ancient movements of whales by looking at barnacles. I'll get to that in the second but first I wanted to mention a couple of other interesting facts. So one thing is this article just describes some of the difficulties in the research on whale barnacles, like it's hard to acquire whale barnacles alive and study them, say, to study their reproduction in the lab, for obvious reasons and for less obvious ones. The obvious reasons would be like they are attached to living whales, and the less obvious reasons would be because these barnacles are not as they're not as hardy from taking them out of their natural environment because, for example, these whale barnacles typically can't seal themselves shut completely, so they can't fully close the door to keep the water inside when you remove them from their original context. So like you find a whale washed up on a beach, the whale barnacles on it will typically die pretty quick, and so no one. The article stresses how nobody really has figured out yet the right way to care for and preserve the lives of these animals once they are taken off of the whale they belong to. But there's another thing I wanted to emphasize, grin Bond describes, which is the kind of the more body horror aspect of the boundary point between whale and barnacle, which is maybe kind of a gray area, is like where one begins and the other ends. Grunbaum writes, quote, each of these barnacles has a shell structure specially evolved to anchor itself into its host's flesh. Many species have chambers within their wall plates into which prongs of whale skin grow upward, strengthening the barnacle's grip. And this further explains actually like why it is hard to access living whale barnacles for research. It's not just a question to kind of like popping one of them off. It would generally require cutting into the whale's flesh to separate the barnacle from the whale. Oh yeah, yeah, I mean this, you know, comes back to like why do the gray whales have their their signature appearance, And a lot of it is like part of its the barnacles, but also like these gray sort of splotches on their body scars from various things, including scars from where the barnacles were previously attached. Yeah, yeah, scars, because they're like, you know, they really like grab a hold they get in there. Another thing I've read about is that apparently areas underneath the barnacles tend to become depigmented on whale skin, so you can often see them by that there'll be like a different shade than the surrounding skin. Now we're gonna about to get into a really interesting area here, because you know, the thing about living your full life on a migratory large mammal like this is that your life cycle is intrinsically tied to the movements in life cycle of your host species, that's right, and partially for this reason, there's so much we don't know about the whale barnacle life cycle. There's things we don't know about their cycles and their reproduction. They're just hard to study. So they seem to mate with other barnacles nearby on the same whale, but they wait until the whales go to their coastal breeding and calving grounds to release their larvae. And these larvae are probably guided by an attraction to a chemical signal that helps them find the whale skin. This could be a chemical emitted by other barnacles already present. So maybe there's kind of a you know, I don't think korum sensing is the right word. That's from different but you know, they sense a congregation of their kind, or it could be a biosignature from the skin of the whale itself. Maybe they're attracted to some kind of signature mammalian molecule. They also have to do some crawling around on the whale as larvae before they cement themselves down, because you don't just go anywhere on the whale. There are favored regions of the whale's body, often the forehead, the tail, and the forward facing edges of the flippers, and I think this is because it increases their access to flowing water and the plankton in it. But finally, there's a really big interesting thread in this article that's about studying the chemical composition of whale barnacle shells to determine where whales travel. So barnacles are there, you know, their shell builders. They are constantly building up new layers of their calcium carbonate plates, And at some point researchers figured out that you could look at the layers of these plates kind of like tree rings, but by analyzing the ratio of oxygen isotopes in each layer, you couldn't just tell, you know, it's not just counting the tree rings. You could actually say a lot about the properties of the water in which each layer was formed, So what was the temperature of the water, what was the salinity, etc. And actually you could then compare that information to things we know about different regions of the ocean at different times, and this would allow you, by proxy to roughly track the migration history of the whale on which a barnacle lived by peeling back and analyzing the mini layers of its plates and Researchers initially studied this on the shells of living or recently living barnacles, but it turns out you could even do this with fossilized remains of whale barnacles, and by this method you can track the movements not only of living whales or recently living whales, but whales that lived hundreds of thousands of years ago, and that information, in turn can help shed light on unsolved problems in whale evolutions, such as when and why did billeen whales start migrating groombaumb Wrights quote. One hypothesis suggests that it happened around three million years ago, when massive ice sheets started spreading across much of the northern hemisphere. The colder temperatures would have frozen whales out of some of their habitats and put more constraints on where plankton could flourish in Earth's oceans, and the patterns that came to exist in the locations of these, say food and shelter resources, would therefore lead to the establishment of migration patterns over time. We don't know exactly how it happened, but that's one idea, and so it seems like we can now maybe use fossilized whale barnacles to get some insight into what those ancient patterns of migration were when they changed, and what those what those changes might coincide with is, say, in the climate sphere. And this of course can help shed light on things today as well. Doesn't just tell us about the past, because understanding when and why ancient whales started changing their migratory patterns, for example, in relationship to ocean temperatures and sea level and so forth, that could help us understand what's likely to happen in the near future with oceans being affected by our rapidly heating planet. So anyway, it was just a few notes from there, but that article What Whale Barnacles Know very interesting worth a read. Yeah, yeah, I mean it's it's interesting to think about. It's easy to dismiss the barnacles. It's just this hanger on, just this sex up parasite of the whale, But there's so much information tied up in the barnacle about the host species. Well, this has been this has been a really fun journey. I've really enjoyed getting to dive in to researching the gray whale. After getting to have this experience with them. I guess some people would probably do this in reverse order to do their research and then have the experience, but for whatever reason, I end up doing it the other way around most of the time. But I enjoyed I kind of that's one way to sort of draw out these experiences. Oh, I don't think it's a bad way at all, experience and then reflect. Yeah. Yeah. By the way, I've cited several authors and sources that were helpful in the research for these episodes, but I'd also like to throw in some hefty things to the local guides at the Ojo de Layabre Lagoon, some of which have been doing this sort of guide work every year for something like thirty five years, as well as the international tour guides that I had there, Keith Hassan and Donna in particular. Everyone was delightful and full of wonderful facts and observations about the whales, and I also really enjoyed the company of the folks that my family toured with. In case any of you out there having to be listening, the great thing about a trip like this is that no one is that they are is just kind of sort of into Wales like everyone, At least in my experience, everyone was really excited, really into them, and really compassionate for them. So yeah, just a shout out if should any of you be listening. All right, we're gonna go ahead and close the book on this one, but we'll be back with more episodes next week. Just a reminder that Stuff to Blow Your Mind is primarily a science podcast, with core episodes publishing on Tuesdays and Thursdays, but on Mondays we do listener mail. On Wednesday's a short form artifact or monster fact episode, and on Fridays we do Weird House Cinema. That's our time to set aside most serious concerns and just talk about a strange film. Huge thanks to our audio producer JJ Poseway. If you would like to get in touch with us with feedback on this episode or any other, to suggest a topic for the future, to share something interesting, or just to say hello, you can email us at contact at stuff to Blow your Mind dot com. Stuff to Blow Your Mind is production of iHeartRadio. For more podcasts from my heart Radio, it's the iHeartRadio app, Apple Podcasts, or wherever you're listening to your favorite shows.

Stuff To Blow Your Mind

Deep in the back of your mind, you’ve always had the feeling that there’s something strange about re 
Social links
Follow podcast
Recent clips
Browse 2,718 clip(s)